Depends on how much it sets you back... I'd just buy a proper LSD.

Fair enough, Any you would recommend. Found a XR6T one second hand for $300 on ebay.

That seems like a decent price. Brand new your looking at about $700 or so.

alot of v8's have underdrive kits that replace a few pulleys rather than just the harmonic balancer, this keeps everything the same speed and also achieves more of an 'underdrive' i think the reason for this style not being commercially available for b series just yet is because it needs re-tuning.
the commercially available underdrives everyone here is talking about also slow your accessories a fraction, but i'm assured my a manufacturer this has no negative effect whatsoever.... though my opinion is if the given accessory is spinning slower it's not as effective (like trying to drive with no power steering belt: exagerated or perhaps the air-con not as effective) but if it's not enough reduction to worry about, is it achieving as much as it could be at the crank? if that makes sense....
so yes you can fit an underdrive to any motor, weather theres one commercially available or not is another question, but enough money can buy you anything. I have heard mostly good things about the normally available underdrives but not likely to be more than 2kw gain on dyno which is almost unreadable.It's more a driveability mod i believe, like lightening your flywheel.

and on the late model shift kits..... i got advised before purchase that even dual stage shift kits, in vehicles with adaptive shift (all b series & selective a's) will never regain the adaptive strategy untill the kit is completely disconnected. The switch turns the kit off and the box goes back to a default comfortable shift & never adaptive. Unless this has changed recently, which if it has let me know lol

Thanks a lot for your input. What exactly do you mean by adaptive shift? Is that when it will down gear down hills etc.?

no thats grade logic or something. adaptive shift put simply is when you have a au> 4 speed with no power/economy switch. It changes shift patterns and firmness depending on 'driver behaviour' and does a pretty good job.

so your 100% that the bf xr6s have this? i guess if its true then it'll be waste getting a shift kit...
i dont get it though... people say that when its off it returns back to perfect stock. and whats the difference between single and duel? i was going to get a single stage.

only you can confirm if yours adaptive... it's your car after all. i'm just providing information i have, which is obviously limited. I was told the dual stage shift kit will return to 'normal' which is e series auto control normal, without adaptive. a set shift firmness and 'normal' shift patterns.
in a car with adaptive shift, when you've been feeding it 'spirited driving' patterns that it will redline before changing gears in drive, if putting around like an old goat it will change much earlier when you initially give it the berries. Loosing this turned me off putting a shift kit in both my cars.
You should contact shiftkits.com.au

i went back to 5 speed instead, autos make my head hurt, i'm too oldskool.

i just got one from shiftkits.com.au, ill install it and let u know how it goes, im currently doing lots of cheap little things to make it more appealing to the p plater crowd so i can sell it to some young dumb kid.

Lmao Jim. Try taking the turbo off it :p. And I'll be looking forward to hearing from you. You have the 4 speed ZF?

in that case shift kit ftw lol.

let us know how it goes.

ZF is 6 speed. 4 speed is ION ? another name for btr.

Yep, but then ION went bust making it difficult to get hands on tech manuals etc except from those who already have them.

ah really ? That's bad..

who made the 5 speed autos ?

yes its a 4spd, In WA the cool kat p platers can drive anything they like. no power restrictions.

ill keep you informed

You know guys if you get ur car tuned using the sct xcal 3 device your turner can firm up the shifts as part of the process. They can even firm up the shifts only in performance mode or tip tronic so ur not flogging the tranny everytime u drive. Granted the custom tuning process is expensive but at least you know u wont have issues
Cheers

Phil